Loosing video after BIOS changes

Hardware ZimaBlade
,
1

I tried to install TrueNAS on my Zima Blade. It failed with some superblock error.

I tried UEFI settings and BIOS told me I had to change my video settings first. I did that and from then on no video output.

I also tried to reset bridging the RST pins on the board - no change, which is strange as I thought this should word under any circumstances. But maybe I did something wrong.

Maybe I misunderstood something or did not run the right procedure?

Zima_Blade_reset2
Zima_Blade_reset21737Ă—1346 332 KB

Board seems to boot as a can see the keyboard reacting, so it seems to be a problem of video only.

Any hint? tx

2

This isn’t a TrueNAS issue, the BIOS video settings were changed, and the board is now booting with an unsupported display mode. That’s why the keyboard reacts but the HDMI stays black.

The RST-SW header you bridged only triggers a reboot. It does not reset BIOS settings, so it can’t restore video output.

To fix it, you need a full CMOS reset:

  1. Power off and unplug the unit.
  2. Hold the rear BIOS-reset button for a few seconds.
  3. If video doesn’t return, use the CLRTC pads on the board to force a proper CMOS clear.

After that, HDMI output comes back with default settings. Avoid changing “Primary Display” or video-related BIOS options unless you have a recovery console attached.

3

OK, that helps a bit. But …

  • Hold the rear BIOS-reset button for a few seconds.

There is no button with a Zima Blade. At least I can find one.

  • If video doesn’t return, use the CLRTC pads on the board to force a proper CMOS clear.

I was unable to locate that on a Zima Blade (!) board. Any hint?

Kind regards

Wolfgang

4

On the Zima Blade the simplest guaranteed reset is to remove the CMOS battery, wait a few seconds, then put it back in. That forces the BIOS to drop all settings and restores the default video output.

The RST-SW header won’t do that, it only reboots the board, so the wrong display mode stayed active.

Pulling and reseating the CMOS battery brings everything back to factory defaults, including HDMI.

1 Like
5

OK, found it :slight_smile:
This little video was really helpful.